Mr Straw was warned any military action must not harm innocent Afghans
Egypt is not expected to take an active role in any military action against Afghanistan but it is thought the president will take an understanding approach to operations directed at Osama Bin Laden.
President Mubarak has warned against action that would hurt civilians but has made it clear that he regards the Taleban as dangerous extremists.
On Wednesday the foreign secretary had talks with Egypt's most senior cleric Sheikh Mohamed Sayed Tantawi and Arab League Secretary General Amre Moussa.
Both men warned Mr Straw they would only support military action against the perpetrators of the US atrocities, but not innocent Afghans.
Targeting terrorists
Sharing a platform with Mr Straw after their meeting, Mr Moussa said: "Any action that would result in a lot of innocent victims would indeed be a very sad result.
"In addition to thousands we lost as human beings in New York, we would be losing thousands in another place.
"We better not resort to any action that would result in this.
"But a surgical operation to deal with the accused after announcing the evidence on that, this would be something we would understand."
He reiterated that Arab countries would not take part in any planned US-led military action against Afghanistan, although they were all "solidly against international terrorism".
He suggested the best outcome would be for Osama Bin Laden to be put on trial "for all of us around the world to know what exactly happened".
A BBC correspondent says British officials saw this reaction as an endorsement of Western plans to attack the Taleban, while Egyptian journalists saw it as a reprimand to Britain for failing to extradite Egyptians wanted by Cairo on terrorist charges.
Mr Straw's meeting in Cairo with Mr Mubarak is the last engagement of his four-day tour of the region.
Constructive talks
Mr Straw had meetings in Israel late on Tuesday with Israeli Prime Minister Ariel Sharon and Mr Peres.
The British minister described his talks with Mr Sharon as very constructive and cordial, saying they discussed the attacks on the US and agreed on the need for unanimity in fighting terrorism.
The meeting took place after Britain and Israel resolved a row over remarks by Mr Straw, which Israel said implied that it was partly to blame for terrorist attacks against it.
Mr Straw also had talks with the Palestinian legislator, Hanan Ashrawi, during which he stressed the need for the Palestinian Authority to do everything it could to ensure there was a complete halt to violence.
Mr Straw's trip to Israel follows a brief visit to Tehran, where he consulted Iranian leaders on the global crisis following the terrorist attacks on New York and Washington.